That is random noise on the pressure signal and reinstalling or trying a different version will have no effect. It’s probably caused by a mismatch between krita’s tablet settings and how your laptop stylus works
Try Settings -> Configure Krita -> Tablet settings and swap between Wintab and Windows Ink to see if that fixes it. I have a feeling that your laptop stylus will be set up to use Windows Ink so it’s likely that you have krita set to Wintab at the moment. Please try it and report back on what it was to start with and if changing it helps.